1. Field of the Invention
The present invention relates generally to distributing phase information among a number of controllers and relates more particularly to distributing clock phase information among multiple controllers for appropriate synchronization.
2. Description of Related Art
DC-DC converters supply power in a variety of applications, including modular power supplies. Computer or digital equipment applications often call for DC-DC power converters capable of handling widely varying loads. Solutions for these applications sometimes involve specifying large capacity power converters, or high performance power converters. One flexible solution relates to a power converter arranged as a group of modules where modules may be added or removed to meet power specifications.
One goal in providing a power to a system using DC-DC converters is to minimize output current ripple. One technique for reducing input and output current ripple in a multi-module environment is to offset switching phases within the modules to achieve ripple current cancellation. By switching the various modules so that they have synchronous offset phases, the output ripple current tends to be cancelled among the different phases, thereby reducing input and output ripple current. Reductions in input and output ripple current permits smaller capacitors to be used with the power control modules, significantly reducing size and cost for the systems.
One challenge in maintaining synchronous offset phases among the modules stems from the flexibility of the multi-module DC-DC converter. The clock and phase information used by the modules depends on the number of modules used. The number of modules indicates how the clock and phase information is split up to set appropriate switching cycles for synchronized phase offset in the modules to produce ripple current cancellation. In particular, if modules are constructed to be swapped in and out of a system, or ganged together to meet the demands of a power application, distribution of the clock and phase information among the modules becomes extremely difficult, since there is a lack of knowledge of the arrangement of the modules. Prior solutions to overcome this difficulty call for rewiring or manually configuring the multiple module power converter.
It is therefore desirable to procure a method for properly distributing a clock and phase information among multiple modules in a DC-DC converter system.